The present invention relates to structural assemblies used as scaffolding, towers and shoring systems, and more particularly to lightweight, ultra-rigid assemblies that allow for unbraced lengths that are greater than is possible with conventional structural systems.
Structural assemblies used for building scaffolding have a variety of requirements. First, such assemblies must retain structural integrity in a variety of loading conditions. Scaffolding structures are often used to support personnel, equipment, and materials to be used in building construction or renovation. These represent structural loads that are delivered to and removed from platforms within the scaffolding by hoists. The heights to which such loads must be supported can exceed 1500 ft. In addition to vertical loads on the scaffolding structure, lateral loads can be introduced by winds or unbalanced load distributions within the structure itself. The consequences of failure of such scaffolding could entail injury or loss of life to personnel within the scaffolding or on the ground in the immediate vicinity of the site, equipment damage and project delays. Thus, the structural integrity of scaffolding can be crucial.
Scaffolding can also be subject to other demands dictated by the particular application. For example, there may be a requirement for local openings in the lattice structure of the scaffolding to accommodate the loading and unloading of bulky materials or equipment from the hoist at specific elevations. Such openings in the lattice structure can represent potential weaknesses in the overall structure that must be corrected with additional local stiffening. A structural scaffolding assembly must be able to accommodate such local openings and the attendant local stiffening. As a scaffolding system, the structure must also be easily assembled and disassembled using interchangeable parts that are relatively easily transported. Of course, low cost is a factor in any scaffolding design.
The present invention of a high-rigidity structure comprises a plurality of vertical column members, wherein the vertical column members are hollow right cylinders with four equally-spaced radial flanges of equal height extending outwardly therefrom, wherein the flanges have a plurality of regularly spaced holes for mounting structural members.
In an alternative embodiment, the vertical column members are extrusions having flanges integral with the hollow right cylinders. In further embodiments, the hollow right cylinders have an annular cross section, the annulus has an inner diameter of approximately 3 to 6 inches, the flanges extend radially from an outer diameter of the annulus approximately 2-4 inches, and the annulus and flanges have thicknesses of 0.3-0.8 inches.
In yet other embodiments, the invention relates to a hoist platform system comprising a high-rigidity scaffolding structure for supporting an elevated platform, a first hoist for lifting material to a first edge of the platform, and a second hoist for lifting material to a second edge of the platform, wherein access to the platform from the hoists is unobstructed.